The present invention relates to an apparatus for winding a thread onto a bobbin comprising a thread guide connected to a traversing element, a motor-actuated drive wheel and guiding elements for guiding the traversing element along a longitudinal direction of the bobbin, and a sensor for monitoring the traversing motion of the thread guide.
Due to the high accelerations and decelerations of the traversing element, said element is to have as low a mass as possible and therefore preferably takes the form of a flexible member, albeit rigid in traversing direction for transmitting tensile forces. Suitable, known traversing elements are, for example, strings, wires, cables, bands or belts.
In a winding apparatus of said type described in EP-A-0 453 622, in which the traversing element is formed by a string, guide pulleys and the string are disposed rigidly on a common carrier plate. Upon each reversal of motion of the thread guide and hence of the string, one of the two strands of the string running from the thread guide via the guide pulley to the drive wheel is tightened and the other is slackened, thereby impairing the positioning accuracy of the thread guide and limiting the traversing speed.
An object of the invention is therefore to provide a winding apparatus in which tension variations in the traversing element formed by a flexible member, e.g., a string, belt, cable, band or the like, are substantially eliminated in the region of the reversing points such that very high traversing speeds and very high thread guide positioning accuracies are achieved.